As known to those skilled in the art, gas producing wells typically employ a gas lift plunger slidably arranged within tubing of a well. The plunger slidably moves vertically within the tubing as the gas well is cycled between shut-in and opened conditions. More specifically, the plunger vertically rises under the effect of sufficient gas pressure to drive or lift the plunger and a slug or liquid, typically oil, above it to the surface or well head while isolating the base of the liquid slug from the gas lifting the plunger. After the slug of liquid is delivered to the surface and the pressure of the gas flowing from the well tubing has decreased below the gravitational force or energy acting on the plunger, the plunger falls back or is returned to its initial position in the well tubing.
One conventional lubricator assembly includes an elongated rigid tubular member defining an interior chamber closed at an upper end thereof. A strike plate or plunger is arranged in the chamber of the elongated tubular member toward a lower end portion thereof. An elongated coil spring is also arranged within the interior of the chamber between the closed upper end of the tubular member and the lower plunger. Typically, the coil spring is made from a conventional steel and is intended to absorb the relatively high impact forces or loads generated by the plunger and thereby protecting the remaining structure of the lubricator assembly against damage from the relatively high pressure liquids and gases acting on the lubricator assembly.
Under some operating conditions, and for various reasons, the spring arranged in operable combination with the lubricator assembly sometimes fails and collapses. On occasion, the failure of the spring can occur within relatively short periods of time. Of course, the collapse and failure of the spring results in the plunger being driven, under the relatively high force or loads acting thereon, against the closed end of the tubular body. Without a sufficient bias on the plunger, the relatively high forces or loads acting on the well head are known to be sufficient to cause significant damage to the tubular body of the lubricator assembly. As such, operation of the well is halted to effect the necessary repairs and or replacement of broken and damaged components.
Thus, there is a need and continuing desire for a well head lubricator assembly which is designed to overcome the heretofore and other known problems and drawbacks.